
.triangleUp (@width: @width/2, @height, @color) {
  height: 0;
  width: 0;
  border-bottom: @height solid @color;
  border-left: @width solid transparent;
  border-right: @width solid transparent;
}

.triangleRight (@width: @width/2, @height, @color) {
  height: 0;
  width: 0;
  border-left: @height solid @color;
  border-top: @width solid transparent;
  border-bottom: @width solid transparent;
}

.triangleDown (@width: @width/2, @height, @color) {
  height: 0;
  width: 0;
  border-top: @height solid @color;
  border-left: @width solid transparent;
  border-right: @width solid transparent;
}

.triangleLeft (@width: @width/2, @height, @color) {
  height: 0;
  width: 0;
  border-right: @height solid @color;
  border-top: @width solid transparent;
  border-bottom: @width solid transparent;
}